Telescoping extension ladder



April 27 1926. v 1,582,794

C. W. SMITH ET AL TELESCOPING EXTENSION LADDER Original Filed p 7 1924 2Sheets-Sheet 1 mgmgm gwventots April 27 1926. 1,582,794

C. W. SMITH ET AL TELES COPING EXTENS ION LADDER Original Filed pt. 2'7.2 2 Sheets-Sheet 2 Patented Apr. 27, 1925.

UNITED STATES PATENT OFFICE.

CHARLES W. SMITH, OF BLUFFTON, AND EARNESI L. THOMIPSON, 0F FORT WAYNE,

INDIANA.

TELESCOPING EXTENSION LADDER.

Griginal application filed September 27, 1824, Serial No. 740,236.Divided and this application filed March 8, 1928.

To (ZZZ 207mm 714' may concern:

Be it known that we, CHARLES 1V. SMITH and Ennnrsr L. THOMPSON, citizensor the United States, residing, respectively, at Blutlton, in the countyof Wells and State of Indiana, and Fort Jayne, in the county of Allenand State of Indiana, have invented certain new and usefulImprovements'in Telescoping Extension Ladders; and we do hereby declarethe following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

Our invention relates to power-driven fire trucks, but more particularlyto motor actuated ladders mounted upon such trucks, and to means wherebythe main and extension ladder sections may be quickly and ace ratclyelevated into operative position when desired or required.

The present application is adivision or our co-pending applicationSerial No. 740,- 236, iiled September 27, 1924-,

An object of our invention is the production or fire-fighting apparatusof the character indicated, wherein is combined extreme simplicity ofconstruction, durability and etliciency of the highest obtainabledegree, the same power plant being employed for locomotion and forladder manipulation with speed, accuracy and precision.

With the foregoing and other objects in view the present invention illbe hereinafter particularly described and then pointed out by the claimsfollowing.

In the accompanying drawings which form part of this application forLetters- Patent, and whereon corresponding numerals indicate like partsin the several views:

Figure 1 is a top plan view of this invention showing the major part ofthe truck chassis, the ladder sections, and ladder operating mechanism;

Figure 2 is a fragmentary view showing in side elevation the laddersections in a raised vertical position, but still nested or collapsed;

Figure 3 is also a fragmentary vertical sectional View taken onthe line33 of Figure 2, showing thelower end of the lower- Serial No. 93,162.

most ladder section raised to a vertical position;

Figure 4: is a horizontal sectional view tlniough one ladder section;and

Figure 5 is a fragmentary view also in horizontal section of one side ofa series of ladders when nested or collapsed into the position indicatedby Figure 2.

Reference being had to the drawings and numerals thereon, 1 indicates atruck chassis, which may be of any suitable construction or proportions,mounted upon wheels 2, only two of which are shown by the. drawings, andprovided with a suitable power and propulsion plant such as showndiagrammatically at 3. fit as side of the main driving shaft 1 andbracketed to the truck frame 1 in suitable bearings is a powertransmission shaft 5, driven from the engine 3 by agency of a sprocket 6and chain 7, and provided at its other inner end with two fixed beveledpinions 8 and 9. The former of these pinions 8 meshes constantly with abeveled gear 10 carried by a short stub shatt mounted in a journal box11, the said shat't having at its opposite end a fixed beveled pinion orspur wheel 12. This spur pinion l2 meshes constantly with two oppositelydisposed driven gears 13 and 1% mounted loosely upon a worm-shaft 15,separated by the spacing sleeve 16, and provided upon their outer tacoswith clutch members 17 and 18, respectively, which rotate constantly inopposite directions with the said gears, the while constituting areversible clutch.

Splined upon the said worm-shaft 15, so to permit of slight longitudinalmovement, are the movable clutch members 19 and 20, arranged and adaptedto be actuated by a rectangular frame or compound lever 21, pivoted asat 22, and provided with a handle 23 by which controlled, to move one orthe other of the clutch members 19 or 20, into cooperating engagementwith its particular clutch member 17 or 18 according to the requirementsas will more clearly appear in connection with a description ofoperation to follow.

The shaft 15 rotatably journalled atits ends in transverse framemembers'Qt, 25, is provided upon its innermost end with a worm 2Gmeshing with a segmental rack 2'4", the latter keyed to a shaft 29 whichin turn is supported in uprights 29, 29, rising from the side sills ofthe truck chassis 1 as best shown by Figures 2 and 3. Rigidly secured tothe said transverse .shaft 28 also are the side rails of a main laddersection 30, which normally occupies the horizontal position indicated bydotted lines in Figure 2 of the drawings, but is capable of beingrotated into vertical position as will later appear.

By preference the main ladder section 30, as also the co-acting flyladders 31, 32 and 33, are made of sheet metal substantially asindicated by Figures 4 and 5 of the draw ings. That is to say, theirside rails are of tubular form made up of reversely arranged channels 34and 35, the latter enclosing the former, and connected by through bolts36 surrounded by tubular spacing membersv 37, as clearly shown by Figure4. Between the inner sides of ladder members and the outer surfaces ofthe members 34 of each ladder section, there is provided acontinuouslongitudinal clearance or space 38, into which is loosely and slidablyfitted the member 35 of the adjacentladder sections, and in this mannerthe several ladder sections 30, 31, 32 and 33 are interlinked as shownby Figure 5, in telescopic relation. At suitable intervals between thetie rods or bolts 36 the side rails of all ladder sections are alsoconnected by ladder rungs 39, while near opposite ends of all laddersections, upon their outer faces, are pivotally mounted inner and outerhoisting pulleys or sheaves and 41 respectively, for purposes that willlater appear. The uppermost of the fly ladders 33, has no upper sheaves41, nor are there sheaves 40 at its opposite end, but in place of thelatter at both sides of this ladder section 33, there are openingsthrough the ladder sides and in these are journalled pulleys 41occupying positions; at right angles to the sheaves 41.

Journalled in opposite sides of the truck chassis 1 as at 42, 2, is adouble Windlass or hoisting reel 43, 43, mounted loosely upon atransversely positioned driven shaft 44 having keyed upon one end adriven gear constantly in mesh with the driving pinion 9 hereinbeforementioned. At its opposite end the Windlass or hoisting reel 43 isprovided with a clutch 46, and a clutch lever 47, by which said reel canbe temporarily locked to its constantly revolving shaft 44, or instantlyreleased therefrom as occasion requires. and upon one side of reel 43 isa brake drum 48 over which runs a band brake 49, operated by abrake-lever 5O pivotally mounted upon the truck frame for retaining theladder sections in a distended position or for lowering them back totheir Adjacent the reel clutch 46- normal nested position, the brakelever being fitted with an ordinary pawl and cooperating rack, indicateddiagrammatically at 51 for holding the fly ladders in Opera tiveposition after raising.

This being a description of our present invention in one form ofembodiment, its use and operation in the form shown and described willnow be briefly set forth as follows:

The truck having been driven to its point of service in the usual mannerunder the power of its engine, the brakes are applied, and the enginede-clutched or disconnected from its driving or propelling mechanism.Power now transmitted to the auxiliary shaft 5, by agency of such meansas chain and sprocket 7, 6, drives the gears 13 and 14 in reversedirections by agency of pinions 3 and 1.2 and the intermediate gear 10.Normally the said gears 13 and 14 run idly upon the shaft 15, but whennow the clutch members 13 and 20 are interlocked by a throw of handle 23in a rearward direction, the said shaft 15 and its worm 26 operate torock segment 27 on its center from the position indicated by dottedlines of Figure 2, to that indicated by full lines, thereby elevatingthe main and fly-ladder sections 30, 31, 32 and 33, still clustered,nested or withdrawn, to the vertical position shown by full lines insaid Figure 2.

The fly ladders 31, 32 and 33 may now be quickly extended or shot upwardfrom the main ladder 30, by agency of the ladder extension clutch 46,and its controlling lever 47. A throw of this lever 47 instantly couplesthe double hoisting reel 43, 43 to its supporting shaft 44, the latterconstantly rotated by drive shaft 5 through pinion 9 and the gear 45.

This accomplished, both ends of the continuous hoisting wire cable 52are quickly coiled upon the power driven reels 43, 43, from which theypass over guide sheaves 53, adjacent the main ladder section 30, thenceover oppositely disposed sheaves 41, 41, at the upper end of ladder 30,thence over sheaves 40, 40 and 41, 41, upon opposite ends of fly-ladder31, over similar sheaves 40, 40 and 41, 41 upon opposite ends of laddersection 32, and finally over sheaves 41, 41 located in openings near thebottom and through the side rails of the outermost ladder section 33.

By this means the ladder sections are quickly extended, flanges 35, 35of each guided and running freely in the spaces or grooves 38, 38provided in adjacent sections for their interconnection. Upon reachingthe desired elevation or extension, clutch 43 is disconnected, and thehand brake 4849 being simultaneously set by a throw of the brake lever50, is there retained by action of the pawl and ratchet mechanism 51,until manually released for the purpose of returning the ladder sectionsto normal positions.

When thus released the ladder sections are lowered or returned to aclustered vertical position by gravity under control or" the brake lever50, the operator preventing too rapid return by agency of the brake bandi9 applied to the brake drum 48 with more or less pressure according tocircumstances, and thus gradually paying out the hoisting cable from thereels e3, as required.

Having reached the position indicated by Figure 2, the ladders are nextreturned to their normal horizontal position in the following manner Athrow of the reversible clutch lever 23 in a forward direction nowserves to interlock the clutch members 17 and 19 thereby rotating theworm-shaft 15 in the opposite or reverse direction from thathereinbefore described, at the same time rocking the scg mental rack 27from the position indicated by full lines, to that indicated by dottedlines, in Figure 2 of the drawings, thus lowering the ladder sectionsupon the transverse shaft 28 as a center into their normal horizontalposition.

Having thus described our invention in one operative form ofconstruction, what we new claim and desire to secure by Letters Patentis:

1. In an extension ladder, a series of ladder sections, each sectionconsisting of side rails and connecting rungs, each side rail consistingof a pair of channel iron strips of different widths, the strips of eachrail being reversely arranged with the wings of the strips spaced apartto form parallel grooves at the opposite edge portions of the rail, thewings of one of the strips of one rail extending into the grooves of twoadjacent rails to provide a sliding connection between the rails.

2. In an extension ladder,a series of ladder sections slidablyinterconnected and each consisting of a pair of side rails and crossrungs, each side rail consisting of a large channel iron strip and asmall channel iron strip, the Webs of the strips being spaced apart andthe wings of the strips extending in opposite directions to provide atopposite sides of each rail a pair of flanges and a pair of grooves, theflanges and grooves of adjacent ladder sections being slidablyinterconnected to permit the ladder to be extended.

3. An extension ladder comprising main and extension sections havingtubular side rails, each rail formed of reversely arranged members ofsubstantially U-shape held in fixed relation by through bolts connectingopposite sides of each ladder section, in combination with longitudinalflanges upon each of said side rails arranged and adapted to run in.grooves upon the corresponding side rails of adjacent ladder sections.

l. An extension ladder including in combination a series of slidablyinterconnected ladder sections, each section consisting of side railsand rungs, each rail consisting of channel irons of different sizes withthe wings of the smaller channel iron extending into the larger channeliron and abutting against the web of the latter, the wings of the twochannel irons being spaced apart to provide grooves at the opposite edgeportions of the rail.

In testimony whereof we afiix our signatures.

CHARLES SMITH. EARNEST L. THOMPSON.

